package rstplus;

/*
 * RST - Russian SMS transliterator
 * Copyleft 2011
 * Author: Alexey Shat'ko (Алексей Шатько), rstapp@yandex.ru
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this source code (in file copying.txt); if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


import java.util.Stack;
import javax.microedition.lcdui.*;

public final class DisplayableStack {

    private Stack stack;
    private Display disp;
    private Displayable base;

    public DisplayableStack(Display disp, Displayable base) {
        this.disp = disp;
        this.base = base;
        stack = new Stack();
        disp.setCurrent(base);
    }

    public void push(Displayable d) {
        disp.setCurrent(d);
        stack.push(d);
    }

    public void pop() {
        if (stack.empty()) {
            disp.setCurrent(base);
        } else {
            stack.pop();
            if (stack.empty()) {
                disp.setCurrent(base);
            } else {
                disp.setCurrent((Displayable) stack.peek());
            }
        }
    }

    public void pop(int count) {
        for (int i = 0; i < count; i++) {
            if (!stack.isEmpty()) {
                stack.pop();
            }
        }
        if (stack.empty()) {
            disp.setCurrent(base);
        } else {
            disp.setCurrent((Displayable) stack.peek());
        }
    }

    public void popAll() {
        stack.removeAllElements();
        disp.setCurrent(base);
    }

    public Displayable peek() {
        if (stack.empty()) {
            return base;
        } else {
            return (Displayable) stack.peek();
        }
    }
}
